1. Field of the Invention
The invention relates to a straight-way and stop valve in which at least three identical discs are arranged in stacked, sealing engagement, with each disc having radial openings wherein the two outer discs are stationary while the central disc is rotatably mounted therebetween and has an actuating means coupled thereto.
2. Description of Prior Art
A disadvantage of known valves of this type is that when the valve is in its closed position and experiences a temperature rise, the fluid which is trapped in the passages in the central disc may expand so that the discs may separate from one another. This danger exists because the discs are formed with identical passages and, accordingly, have identical sealing surfaces so that the passages of the central disc, which are filled with fluid, are closed on both sides by the web-shaped sealing surfaces of the outer discs. A further disadvantage of such a design is that when the valve is opened, the flow of fluid entering the pack of discs leads to increased resistance to flow through the passages. Such a valve design encounters the problem that when the valve is in its throttled position, the fluid flows into the conduit at high speed and with high angular momentum at the discharge side of the valve.
The problems and disadvantages encountered are overcome by providing a straight-way and stop valve of the present invention which is reliable in operation and simple in construction.